Actually Microsoft and Apple settled their lawsuit out of court. Neither company wanted to pursue litigation. Apple wanted MSOffice, and Microsoft wanted some technologies from Apple as well, but I'm not sure which ones they got. As for the GUI, Apple perfected it, then ruined it with OS X in some respects, while Microsoft added the Right-Click Properties option, which I think made Windows95 more consistent than anything that came before. Still the question is the Start icon, a button? a menu? and in Vista it will remove the word start, so no one really knows what it is.
Just an update on the virus thing I mentioned earlier... http://www.moneyweb.co.za/business_today/906076.htm